Thomas a



(No Model.)

- T. A. EDISON.

I-NCANDESGENT ELECTRIC LAMP. No. 317,631. Patente'dMaJy 12, 1885.

WITNESSES INVBN TOR d1 7 at 5 ATTORNEYS.

r a. PETERS, Phuto-Lilhogmpher, Washlqglon. D. c.

NlTED STATES PATENT rricn.

THOMAS A. EDISON, OF MEN LO PARK, NEW JERSEY, ASSIGNOR TO THE EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.

l NCANDESCENT ELECTRIC LAMP.

ESPECIFICATION forming part of Letters Patent No. 317,631, dated May 12, 1885.

Application filed November 29, 1881.

To all whom it may concern:

Be it known that I, THOMAS A. EDISON, of Menlo Park, in the county of Middlesex and State-of New Jersey, have inventeda new and useful Improvement in Electric Lamps, (Case No. 374,) of which the following is a specification.

WVhen it is intended that an incandescing electric lamp shall be readily removable from or replaceable in its socket or support,and the connection through the lamp from the socket is automatically completed or broken by the act of placing in or removing from position, it is necessary that thelamp be provided with a base, in or upon which are secured contactplates, forming terminals of the wires leading into the lamp and to the incandescing conductor. Such bases have hitherto been made of several pieces of metal or of wood, or of wood and metal, secured to the lamp by a greater or less quantity of wax or cement.

The object of this invention is to provide the incandescing electric lamp with a base of simpler and cheaper construction; to which end it consistsin a base formed upon the neck of the lamp entirely of an insulating plastic material, to which are secured, preferably in the process of manufacture, the necessary contact-plates, such plates being joined to gether and held upon the neck of the lampglobe by the plastic material. These contactplates are preferably in different horizontal planes, and one is a screw-ring, the location of the plates in different horizontal planes permitting the lamp to be revolved while the base is entering a socket without short-circuiting the socket.

In the drawing is shown a lamp and the contact as rings in elevation, while the portion of the base seen is in section.

A is the exhausted globe inclosing the car (N0 model.)

h is the base proper, which is formed in one piece directly upon the neck and bottom of the lamp by molding therein in proper shape a suitable quantity of insulating plastic material. A convenient method of doing this is shown in my prior application,No. 34, 651,filed May 81, 1881, which is briefly as follows: To d a wire, is attached, and tof a wire, 6. g is twisted to the leading-in wire a, and e to b. The contacts are then placed within a mold, the neck of the lamp inserted and held in position, and the space between the contacts and the wire filled with the plastic material. The latter having hardened the lampneck is with drawn from the mold.

The contact plates, it will be seen, are joined together and supported upon the neck of the lamp by the hardened plastic material. The method is given as typical only, as it is evident that the invention may be carried into effect in many other ways and without the use of a mold at all.

I do not claim herein the method of molding the base directly upon the lamp, nor the mold therefor, as such forms the subject-matter of the application hereinbefore noted; but

hat I do claim is- 1. In an incandescing electric lamp, the combination, with the glass inclosing-globe and the neck thereof, of contact-plates joined together and held upon the neck of the lamp by plastic material, substantially as set forth.

2. In an incandescing electric lamp, the combination, with the glass inclosingglobe and the neck thereof, of contact-plates located in different horizontal planes, said plates being joined together and held upon the neck c of the lamp by plastic material, substantially as set forth.

3. In an incandescing electric lamp, the combination, with the glass inclosing-globe and the neck thereof, of contact-plates, one 5 of which is a screw-ring located in different horizontal planes, said plates being joined together and supported upon the neck of the lamp by plastic material, substantially as set forth.

THOS. A. EDISON.

Witnesses:

PAUL D. DYER, WM. H. Mnanowononr. 

